While city public schools are ramping up rules against cellphones in class, one city college is actually encouraging its student body to check their phones more often.

Baruch College students searching for an open computer on campus, assignments for a missed class, and even their best friends this fall semester now need only check their mobile phone for the info.

The City University of New York’s business school has launched a free service aimed at reaching students on the devices, which accompany them wherever they go.

“These people live on their phones and they structure their lives on the spot,” said Arthur Downing, chief information officer at Baruch. “We want to tap into that.”

The service has the ring of a discount airline, but AirBaruch is sweeping the ranks of underclassmen at a frenetic pace.

Provided by Rave Wireless Inc., a company that tailors cellphone features to college students, AirBaruch allows students to locate available study rooms and openings at any of the 15 computer labs on campus without setting foot in them.